Principal Investigators Drs. Rudolph Leibel, Michael Rosenbaum, Robin Goland Purpose of Study To identify the genes responsible for early-onset type 2 diabetes by studying parents and siblings of people with type 2 diabetes that was diagnosed prior to age 25.  Subjects undergo a history, physical exam and lab tests including a rapid intravenous glucose tolerance test. Ideal Candidate:  Siblings, mothers, fathers of people with type 2 diabetes diagnosed prior to age 25 Exclusion Criteria:  Subjects younger than 8 yrs old Time Commitment:  1 visit for history, exam and blood tests including a glucose tolerance test, about 1-2 hours.